Cleaning system and method

ABSTRACT

A cleaning system and method includes a screen for removing lint and other large solids from cleaning solvents. The dirty solvent is discharged from the cleaning receptacle at a location spaced from the screen and the lint and other solids accumulate upon the screen while the solvent passes through the screen where it is collected in a sump. At least a portion of the solvent in the sump is returned to the cleaning receptacle and control means controls the discharge rate of the solvent from the receptacle, either in response to the liquid level in the sump or to the flow rate of the liquid being returned to the receptacle, to maintain the solvent in the sump out of contact with the screen. Periodically the lint which has accumulated on the screen is scraped from the screen and discharged by way of a trash conveyor.

[111 3,823,823 July 16, 1974 1 1 CLEANING SYSTEM AND METHOD [75] Inventors: Henry J. Dokter, Lansing; Robert P.

Clark, Barrington, both of 111.

[73] Assignee: F. W. Means & Company, Chicago,

Ill,

[22] Filed: Apr. 4, 1972 [21] Appl. No.: 240,980

[52] [1.8. Ci 210/79, 210/110, 210/125, 210/162, 210/413 [51] Int. Cl Bold 29/04 [58] Field of Search 210/65, 66, 79, 98, 106, 210/107, 167, 400, 196, 110, 125, 129, 159, 162, 413

[56] References Cited UNITED STATES PATENTS 955,843 4/1910 Bossert 210/413 X 1,653,204 12/1927 Dahlin 210/125 X 1,691,862 11/1928 Thomson et a1 210/98 2,142,726 l/1939 Hetzer 210/167 X 3,194,399 7/1965 Harms..... 210/106 X 3,279,604 10/1966 Leviel 210/125 X 3,291,562 12/1966 Anderson 210/167 X 3,722,684 3/1973 Maestrelli 210/ 1.67

Primary Examiner-Charles N. Hart Assistant Examiner-[vars Cintins Attorney, Agent, or Firm-Molinare, Allegretti, Newitt & Witcoff 5 7] ABSTRACT A cleaning system and method includes a screen for removing lint and other large solids from cleaning solvents. The dirty solvent is discharged from the cleaning receptacle at a location spaced from the screen and the lint and other solids accumulate upon the screen while thesolvent passes through the screen where it is collected in a sump. At least a portion of the solvent in the sump is returned to the cleaning receptacle and control means controls the discharge rate of the solvent from the receptacle, either in response to the liquid level in the sump or to the flow rate of the liquid being returned to the receptacle, to maintain the solvent in the sump out of contact with the screen. Periodically the lint which has accumulated on the screen is scraped from the screen and discharged by way of a trash conveyor.

, 36 Claims, 4 Drawing Figures i5: FILTER PUMP FLOW 32 METER PATENTEBJI'IH 6 m4 SHEU 1 0F 2 'CLEAN NG RECEPTACLE PUMP FLOW COLLECTOR 62 V I4 32 I METER Pmmmmw 3.823323 SHEET 2 OF 2 CLEANING 2 TRASH RECEPTACLE. 3 COLLECTION 1 CLEANING SYSTEM AND METHOD BACKGROUND AND SUMMARY OF THE INVENTION This invention relates to a cleaning system and method and, more particularly, to a system and method in which lint and other large solids are removed from the cleaning system.

In conventional cleaning systems, components have been provided for separately removing lint, hair, buttons and other large solid particles from the cleaning solvent prior to passing the solvent through the system filter. The advance removal of these large solids from the solvent prolongs the operating cycle of the filter employed in these systems by reducing the need for frequent flushing and cleaning of the latter and also prevents damage to pumps and other moving parts in the system. In the past, such solids removing components generally have comprised a lint trap which functions satisfactorily where the. quantity of lint and other large solids is not excessive. However, such traps have been found to be inadequate for use in certain modern cleaning processes in which the quantity of lint is frequently 25 to 100 times greater than the conventional cleaning systems, such as where the system is to be employed in the cleaning of heavily solid and linty articles, for example workmen s uniforms and cleaning mops. In practice, it has been found that in systems in which lint is present in excessive amounts that the lint rapidly mats in these prior lint traps necessitating frequent cleaning in order to maintain an adequate flow of solvent through the system.

In the present invention, lint, hair and other large solids are readily removed from the cleaning solvent without excessive matting or plugging of the screen of the present invention and may be automatically and completely removed from the system and discharged to a trash receptacle. Thus, the system and method of the present invention readily provides for cleaning of the cleaning solvent even where the solvent is to be employed in cleaning operations in which excessive lint and other large solids are present. Moreover, in a system and method incorporating the principles of the invention, the level of solvent in a collecting sump, from which the lint and other large solids have been removed, may be readily controlled such that the level of the solvent in the sump does not contact the screen, thus preventing matting of the lint and other large solids on the screen and minimizing the amount of deliquifying of the trash needed prior to discarding the trash. Moreover, in the system and method incorporating the principles of the present invention, pump downand pump up of the receptacle may be periodically accomplished automatically to enhance the cleaning of the solvent and the articles.

.In a principal aspect of the invention, a cleaning'system includes an article cleaning receptacle adapted to contain a cleaning solvent for cleaning the articles therein, screen means for removing lint and other large solids from the solvent, and sump means for receiving the solvent from the screen means. Conduit means is connected to the receptacle for discharging at least a portion of the cleaning solvent onto the screen means and control means controls the flow of the solvent through the conduit means to maintain the solvent in the sump out of contact with the screen means.

In another principal aspect of the invention, the'solvent discharged from the conduit means'is discharged at a location spaced above the screen means and cleaning means is provided for removing the lint and other large solids which have accumulated on the screen means.

In still another aspect of the invention, a method of removing lint and other large solids from the cleaning solvent of an article cleaning system includes discharging at least a portion of the solvent from the cleaning receptacle upon screen means and at a location spaced from the screen means, flowing the discharged solvent through the screen means while retaining the lint and other large solids on the screen means, collecting the solvent which flows through the screen means in a sump, and controlling the rate at which the solvent is discharged from the receptacle so as to maintain the cleaning solvent in the sump out of. contact with the screen means.

In still another aspect of the invention, the method further includes periodically removing the lint and other large solids from the screen means.

These and other objects, features and advantages of the present invention will become evident upon consideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS In the course of this detailed description, the drawings will frequently be referred to in which:

FIG. 1 is a cross sectioned elevation view of a linear article cleaning system constructed in accordance with the principles of the invention,

FIG. 2 is a plan view of the lint screen and trash conveyor taken substantially along line 2-2 of FIG. 1;

. FIG. 3 is a cross sectioned elevation view of a circular embodiment of lint screen and trash conveyor constructed in accordance with the principles of the invention; and

FIG. 4 is a plan view of the lint screen and trash conveyor taken substantially along line 4-4 of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a linear embodiment of cleaning system, such as might be employed in the cleaning of cleaning mops and the like is shown which includes an article cleaning receptacle 10 which is adapted to contain a certain amount of cleaning oil or solvent. The receptacle is of standard construction and will not be described in detail, except that thereceptacle is preferably a rotatabe drum having a suitable aperture through which the mops to be cleaned may be introduced and removed from the drum.

Periodically it becomes necessary to clean the cleaning solvent in the receptacle to remove lint, hair, buttons and other large solid articles, as well as dirt and other contaminants which may have been introduced to the solvent during the cleaning operation. Filters of the type which employ a filter aid, such as diatomaceous earth, have been employed in the past to thoroughly filter the solvent. Prior to introducing the cleaning solvent to these filters, however, it is desirable to first pretreat the dirty solvent to some extent in order to remove large contaminants such as lint, buttons and other large solids, which might otherwise cause early plugging of the filter and damage to -any pumping components in the system or the filter itself.

In the present invention a sump, generally 12 is defined by an open top vessel 14 which is adapted to receive the solvent therein from which the lint and other large solids have been removed. The open top of the sump is closed by a perforated plate or screen 16, which is preferably planar so as to define an elongate planar upper surface 18 upon which the lint and other large solids may accumulate. The perforations 20 in the screen are preferably on the order of 0.050 inch, being large enough to allow the continuous and ready drainage of solvent through the perforations, but small enough to retain lint and other large solids on the upper surface 18 of the screen.

A conduit 22 is connected to the receptacle and is adapted to drain a portion of the solvent from the receptacle and discharge this dirty solvent upon the upper surface 18 of the screen. This draining is accomplished by gravity if the positioning of the system components permits. If this positioning of components does not permit, the solvent may be drained from the receptacle and discharged to the screen by way of a pump. In either event, the conduit discharge 24 is preferably spaced somewhat above the upper surface 18 of the screen 16 such that the dirty solvent impinges the screen so as to form a ring of lint and large solids 26 encircling the area of impingement 28 upon the screen as shown in FIG. 2, which ring progressively closes as the accumulation of lint increases. The formation of ring 26 substantially reduces premature matting of the lint which might otherwise plug the screen perforations 20.

The solvent 30 which passes through the screen 16 is collected in the sump 12 and a conduit 32 communicates with the vessel 14 adjacent its bottom for removal of a portion of the solvent from the sump to return the solvent to the receptacle 10, either directly or preferably by way of a filter 34. Conduit 32 includes a pump 36 for drawing solvent from the sump. The pump 36 is preferably operated continuously, but may be operated intermittently. The pump discharge may either be passed directly through a filter bypass conduit 37 and returned to the receptacle byway of return conduit 38 or it may be passed to the filter conduit 39 and the filter 34 for further removal of minute solids and other contaminants the latter being preferred. From the filter 34 the filter liquid is returned to the receptacle 10 by way of return line 38. It will be seen that by opening valve 41 and shutting valves 42 and 43, direct return will be effected, and by shutting valve 41 in the bypass and opening valves 42 and 43, filtration will occur.

An important feature of the present invention resides in the fact that the screen 16 is continuously drained of the solvent and is never submerged in the solvent 30 and hence matting of accumulated lint is substantially reduced and the accumulated lint is ready at all times for removal from the screen without'further extension deliquification and with a minimum expenditure of mechanical. energy. In order to prevent flooding of the screen 16 and to control the flow rate in the system, a valve 44 is located in gravity conduit 22 and suitable controls are provided to control the opening and closing of the valve 44 which, in turn, controls the rate at which the solvent is discharged from the receptacle. The controls may include either a liquid level control 46 in the sump itself or a flow meter 48 positionedin the pump discharge pathwhich senses the flow rate of solvent from the pump. Either control automatically opens or shuts the valve 44 asnecessary. These controls are particularly important to maintain the maximum solent level 50in the sump 12 at a level such that the screen 16 is not flooded and to effect pump uppump down as will be more fully explained later.

Control of the valve 44 is preferably accomplished in an on'off manner and results in the desired pump uppump down action in the receptacle 10. The mechanical agitation and flooding of the dirty articles in the receptacle 10 which are enhanced by the wide solvent level variations in the receptacle during pump up-pump down, improves the cleaning performance of the present invention.

Screen cleaning means, generally 52, is also provided in the present invention which may take the form of an endless drive chain 54 upon which a plurality of spaced scrapers 56 are carried, such. that the scrapers 56 of one of the flights contact and move linearly across the upper surface 18 of the screen. The scrapers are preferably continuously energizedso as to slowly sweep the lint across the surface 18 of the screen where the lint is further deliquified and the lint is then discharged into a trash collector 58. The trash collector 58 preferably takes the form of amoving conveyor belt 60 which conveys thelint and other large trash 62 away from the screen.

Although the screen 16 is shown in FIG. 1 to be substantially horizontal, it may be desirable to incline the screen somewhat away from the trash collector to prevent flow of the solvent toward the trash collector.

Referring to FIGS.3 and 4, a second preferred circular embodiment of cleaning system is shown in which the lint removing screen is generally circular in shape and the solvent from the cleaning receptacle is pumped to the circular screen, rather than drained by gravity. Since many of the components of the embodiment of system shown in FIGS. 1 and 2 are substantially identical to the embodiment of system shown in FIGS. 3 and 4, like reference numerals will be employed to designate like components.

Referring particularly to FIG. 3, the sump, generally 64, is defined by an open topped circular vessel or tank 66 which is adapted to receive the solent from which the lint and other large solids have been removed. A generally circular planar screen 68 is positioned in the vessel 66 adjacent, but slightly below, its top 70 and defines a generally circular planar upper surface 72 upon which the lint and other large solids are deposited and accumulated.

An elongate radially extending opening 74 is formed in the screen 68 and a conveyor housing 76 depends downward beneath the screen 68 and under the opening 74. The trash conveyor of the present embodiment of invention comprises a moving endless belt conveyor 78 which is positioned in the housing 76 beneath opening 74 and which is movable in the direction indicated by the arrows in FIGS. 3 and 4 by motor 79. The trash v 62 which is removed from the upper surface 72 of the screen 68 drops upon the belt 78 and is conveyed to a suitable trash receptacle 80.

The solvent from the cleaning receptacle is periodically discharged through conduit 22 by way of a pump 82, rather than the valve 44 as previously described since, as shown in FIG. 3, the liquid level in the cleaning receptacle 10 is located below the discharge points 24 at which the solvent is discharged to the screen. Thereby, in the present embodiment drainage from the cleaning receptacle by gravity is impossible and the solvent must be pumped to its discharge point 24 above the screen. However, as with the valve 44 in the previously described embodiment, the pump 82 is preferably controlled by way either of a flow meter (not shown) or a float 46 as shown in FIG. 3, to turn the pump off and on as frequently as necessary to insure that the level 50 of solvent in the sump is maintained within a predetermined range below the screen 68. Pump 82 is preferably a constant flow rate pump which, when actuated, delivers solvent through conduit 22 at a given flow rate which is greater than the maximum flow rate through conduit 32.

As shown in FIGS. 3 and 4, conduit 22 is preferably branched so as to define a pair of spaced delivery extensions 22a and 22b, the discharge ends 24 of which are elevated above the screen surface 18 as previously described. Accordingly, when solvent is delivered through conduit 22, it is discharged upon the. screen at two spaced locations so as to form a pair of expanding rings of lint 26 as previously described.

In the present embodiment of cleaning system, the screen cleaning means, generally 84, takes the form of a rotating set of brushes 86 each of which extend radially from a drive shaft 88 which, in turn, is rotated by a motor 90. Each of the brushes 86, three in number as shown in FIG. 4, extend from the drive shaft 88 to a point adjacent the interior wall 92 of the vessel and the brushes are continuously in contact with the upper surface 72 of the screen. Thus, it will be seen that as the brushes are rotated by motor 90 in, for example, the counterclockwise direction as viewed in FIG. 4, the lint 62 which has accumulated upon the surface of the screen will be swept across the screen to the edge of the opening 74 where it will fall through the elongate opening in the screen upon the conveyor belt 78 and will be conveyed to the trash receptacle 80.

A brief description of the operation of the invention is as follows:

The mops or other articles which are to be cleaned are introduced to the cleaning receptacle which also contains a certain amount of cleaning solvent. As the articles are cleaned, a portion of the cleaning solvent will be discharged, by gravity as shown in FIG. I or by pump 82 in the event that gravity drain isnot feasible, from the receptacle through conduit 22 and is dropped from a location 24 spaced above the screen 16 in FIGS. 1 and 2 or 68 in FIGS. 3 and 4 onto the upper surface of the screen. Where draining through conduit 22 is by gravity as shown in FIG. 1, the drainage rate from the receptacle will be controlled by the opening and closing of valve 44. Where drainage is by pump 82 as shown in FIGS. 3 and 4, the pump will be turned on and off in response to either the float 46 or the flow meter (not shown).

As the dirty solvent impinges the screen in area 28, the lint and other large solids will form the ring 26 about the area of impingement, which ring progressively closes as more solids accumulate upon the screen. The solvent itself freely drains through the perforations in the screen and is collected in sump 12 in FIG. 1 or 64 in FIG. 3.

A portion of the solvent in the sump is continuously withdrawn through conduit 32 by pump 36 and is preferably passed through open valve 42 and the filter 34 where more minute contaminants are removed. The filtrate then passes through open valve 43, and is returned through return conduit 38 to the receptacle 10 where it replenishes the solvent which has been removed from the receptacle.

Since pump 36 is preferably continuously operated, a certain amount of solvent 30 will be continuously removed from sump 12 or 64 and passed through the filter 34 from where this cleaned solvent is returned to the receptacle 10. It willbe appreciated, however, that the flow rate through filter 34, and thus the rate at which the solvent is removed from the sump, willvary between a maximum when the filter 34 has just been cleaned to a minimum just before cleaning. In either event, when the liquid level in sump 12 or 64 has dropped to a predetermined minimum level which is lower than level and which is determined by the setting of the float control 46, the receptacle 10 will contain the maximum amount of solvent and will be in the pumped up condition in which the articles are flooded.

When the solvent level in the sump 12 further drops below this predetermined minimum level, the float control 46 will open valve 44 in FIG. .1 or will startpump 82 in FIG. 3 to commence rapid draining of the receptacle 10. When valve44 is opened or pump 82 is energized, solvent will be drained from the receptacle 10 faster than it is removed from the sump 12 or 64 by pump 36. This rapid draining of the receptacle effects pump down of the receptacle 10, since the solvent is being removed through conduit 22 at a faster rate than it is returned to the receptaclethrough return conduit 38.

When enough solvent has beendrained to the sump 12 or 64 through conduit 22 to raise the solvent level in the sump to the predetermined maximum level 50 which is still below screen 16 in FIG. 1 or screen 68 in FIG. 3, the float control 46 will shut valve 44 or stop motor 82 and the receptacle 10 will be .in its pumped down condition. The volumetric capacity of the sump and the elevation difference between the maximum and minimum solvent levels in the sump are selected relative'to the volume of the receptacle 10, such that the volume of solvent remaining in the receptacle when it is fully pumped down is preferably at least fifty'percent less than the volume of solvent in the receptacle when it is fully pumped up. i

Since scrapers 56 or brushes 86 are preferably continuously energized, the lint and other large solids which accumulate on the screen will be slowly, but continuously moved off the screen to the trash collector 58 in FIG. 1 or 78 in FIG. 3 where they will be conveyed away from the system.

It will be appreciated that although the operation of the system has been described in terms of the float'control 46, that the flow meter 48 may also be employed, in control of the system, since the level of solvent in the sump is a function of the rate at which solvent is removed from the sump. Moreover, it will also be appreciated that the pump employed in the embodiment shown in FIG. 3 may be employed in place of the valve 44 shown in FIG. 1 and vice versa. Moreover, although the screen cleaning scrapers or brushes are preferably continuousin operation they may be operated intermittently in'response to a build up of lint and other foreign matter. I

Finally, it will be understood that the embodiments of the present invention which have been described are merely illustrative of a few of the applications of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

What is claimed is:

1. In a cleaning system,

an article cleaning receptacle adapted to clean articles with a cleaning solvent contained therein, screen means for removing lint and other large solids from the cleaning solvent,

discharge means on said receptacle for discharging said cleaning solvent from said receptacle onto said screen means,

receiving means including an outlet for receiving cleaning solvent from which said lint and other large solids have been removed from said screen means, and

control means controlling the flow of said cleaning solvent through said discharge means in response to the level in said receiving means of the solvent from which said lint has been removed to continuously maintain the solvent from which said lint and other large solids have been removed out of contact with said screen means.

2. In the system of claim 1, wherein said cleaning solvent is discharged from said discharge means onto said screen means at a location spaced above said screen means.

3. In the system of claim 1, wherein said discharge means for removing cleaning solvent comprises sump means, said control means maintaining the level in said sump means out of contact with said screen means.

4. In the system of claim 3, wherein said control means comprises float valve means responsive to the level of cleaning solvent in said sump to control the flow of cleaning solvent through said discharge means.

5. In the system of claim 1, including sump means and second discharge means communicating said sump means with said receptacle for returning cleaning solvent to said receptacle, and means to control the rate that said cleaning solvent is discharged to said screen means such that it is greater than the rate that said cleaning solvent is returned to said receptacle.

6. In the system of claim wherein said control means includes means capable of stopping the flow through the discharge means.

7. In the system of claim 1, including screen cleaning means for removing lint and other largesolids which have accumulated on said screen means.

8. In the system of claim 7 wherein said screen cleaning means comprises means which moves the accumulated lint and other large solids to an edge of said screen means and collecting means for removing the lint and other large solids from said edge.

9. In the system of claim 7 wherein said screen means comprises a stationary flat perforated member having a planar surface facing said discharge means, and said screen cleaning means comprises scraping means movable across said planar surface to at least periodically remove accumulated lint and other large solids from said surface. g i

10. In the system of claim 7 wherein said screen means is circular and said screen cleaning means rotatesrelative to said circular screen means.

11. In the system of claim 1 wherein said receiving means comprises sump means, conduit means for removing solvent from said sump means and returning said solvent to said receptacle at a predetermined maximum flow rate, and wherein said control means controls the discharge rate of said solvent from said receptacle such that said discharge rate is greater than said predetermined maximum flow rate when said solvent is being discharged to said screen means, but to maintain the solvent level in said sump means out of contact with said screen means.

12. In the system of claim 11 including filter means in said conduit means between said sump means and said receptacle.

13. In the system of claim 11 wherein said control means initiates discharge of said solvent from said receptacle when the level of the solvent in said sump is at a predetermined minimum level and stops said discharge when the level of the solvent in said sump is at a predetermined maximum level at which maximum level the solvent is out of contact with said screen means.

14. A method of removing lint and other large solids from the cleaning solvent of an article cleaning system, comprising the steps of:

discharging at least a portion of the cleaning solvent from the cleaning receptacle upon screen means and at a location spaced from said screen means,

flowing the discharged solvent through said screen means while retaining the lint and other large solids on said screen means, removing the cleaning solvent which flows through said screen means from saidscreen means, and

controlling the rate at which the cleaning solvent is discharged upon the screen means from the receptacle in response to the level and flow rate of the solvent which has flowed through said screen means to continuously maintain the cleaning solvent which is removedfrom said screen means out of contact with said screen means.

15. The method of claim 14 including at least periodically removing the lint andother large solids from said screen means by moving said lint and other large solids across said screen means, and collecting the removed lint andother large solids at a location spaced from the portion of said screen means upon which said cleaning solvent is discharged from said receptacle.

I 16. The method of claim 14 wherein the solvent which is removed from said screen means is collected in a sump, and the rate at which the cleaning solvent is discharged from said receptacle is controlled in response to the level of solvent collected in said sump.

l7. Themethod of claim 14 including returning at least a portion of the cleaning solvent which passes through said screen means to said receptacle, and wherein the rate at which the cleaning solvent is discharged from said receptacle when it is being dis-. charged is greater than the maximum rate at which said solvent is returnedv to said receptacle, whereby the amount of solvent in the receptacle varies. 18. The method of claim 17 wherein the solvent which is removed from said screen means is collected in a sump,; and wherein said cleaning solvent is discharged from said receptacle in response to the level of solventin said sump, and said solvent in said sump is returned to said receptacle.

19. The method of claim 17 wherein said cleaning solventv is periodically discharged from said receptacle to said screen means and a portion of the solvent is continuously returned from said sump to said receptacle.

20. The method of claim 14 including forming a ring of lint and other large solids on the screen means about the location that the cleaning solvent is discharged upon said screen means.

21. In a cleaning system,

an article cleaning receptacle adapted to clean articles with a cleaning solvent contained therein, screen means for removing lint and other large solids from the cleaning solvent,

discharge means on said receptacle for discharging said cleaning solvent from said receptacle onto said screen means,

receiving means including an outlet for receiving cleaning solvent from which said lint and other large solids have been removed from said screen means, and

control means controlling the flow of said cleaning solvent through said discharge means in response to the flow rate from said receiving means of the solvent from which said lint has been removed to continuously maintain the solvent from which said lint and other large solids have been removed out of contact with said screen means.-

22. In the system of claim 21, wherein said cleaning solvent is discharged from said discharge means onto said screen means at a location spaced above said screen means. I

23. In the system of claim 21, wherein said receiving means for removing cleaning solvent comprises sump means, said control means maintaining the level in said sump means out of contact with said screen means.

24. In the system of claim 21, including sump means and second discharge means communicating said sump means with said receptacle for returning cleaning solvent to said receptacle, and means to control the rate that said cleaning solvent is discharged to said screen means such that it is greater than the rate that said cleaning solvent is returned to said receptacle.

25. In the system of claim 24 wherein said control means includes means capable of stopping the flow through the discharge means.

26. In the system of claim 21, including screen cleaning means for removing lint and other large solids which have accumulated on said screen means.

27. In the system of claim 26 wherein said screen cleaning means comprises means which moves the accumulated lint and other large solids to an edge of said screen means, and collecting means for removing the lint and other large-solids from said edge.

28. In the system of claim-26 wherein said screen means comprises a stationary flat perforated member having a planar surface facing said discharge means, and said screen cleaning means comprises scraping means movable across said planar surface to at least periodically remove accumulated lint and other large solids from said surface.

29. In the system of claim 26 wherein said screen means is circular and said screen cleaning means rotates relative to said circular screen means.

30. In the system of claim 21 wherein said receiving means comprises sump means, conduit means for removing solvent from said sump means and returning said solvent to said receptacle at a predetermined maximum flow rate, and wherein said control means controls the discharge rate of said solvent from said receptacle such that said discharge rate is greater than said predetermined maximum flow rate when said solvent is being discharged to said screen means, but to maintain the solvent level in said sump means out of contact with said screen means.

31. In the system of claim 30 including filter means in said conduit means between said sump means and said receptacle.

32. A method of removing lint and other large solids from the cleaning solvent of an article cleaning system, comprising the steps of:

discharging at least a portion of the cleaning solvent from the cleaning receptacle upon screen means and at a location spaced from said screen means,

flowing the discharged solvent through said screen means while retaining the lint and other large solids on said screen means, removing the cleaning solvent which flows through said screen means from said screen means, and

controlling the rate at which the cleaning solvent is discharged upon the screen means from the receptacle in response to the flow rate of the solvent which has flowed through said screen means to continuously maintain the cleaning solvent which is removed from said screen means out of contact with said screen means.

33. The method of claim 32 including at least periodically removing the lint and other large solids from said screen means by moving said lint and other large solids across said screen means, and collecting the removed lint and other large solids at a location spaced from the portion of said screen means upon which said cleaning solvent is discharged from said receptacle.

34. The method of claim 32 including returning at least a portion of the cleaning solvent which passes through said screen means to said receptacle, and wherein the rate at which the cleaning solvent is discharged from said receptacle when it is being discharged is greater than the maximum rate at which said solvent is returned to said receptacle, whereby the amount of solventin the receptacle varies.

35. The method of claim 34 wherein said cleaning solvent is periodically discharged from said receptacle to said screen means and a portion of the solvent is continuously returned from said sump to said receptacle.

upon said screen means. 

2. In the system of claim 1, wherein said cleaning solvent is discharged from said discharge means onto said screen means at a location spaced above said screen means.
 3. In the system of claim 1, wherein said discharge means for removing cleaning solvent comprises sump means, said control means maintaining the level in said sump means out of contact with said screen means.
 4. In the system of claim 3, wherein said control means comprises float valve means responsive to the level of cleaning solvent in said sump to control the flow of cleaning solvent through said discharge means.
 5. In the system of claim 1, including sump means and second discharge means communicating said sump means with said receptacle for returning cleaning solvent to said receptacle, and means to control the rate that said cleaning solvent is discharged to said screen means such that it is greater than the rate that said clEaning solvent is returned to said receptacle.
 6. In the system of claim 5 wherein said control means includes means capable of stopping the flow through the discharge means.
 7. In the system of claim 1, including screen cleaning means for removing lint and other large solids which have accumulated on said screen means.
 8. In the system of claim 7 wherein said screen cleaning means comprises means which moves the accumulated lint and other large solids to an edge of said screen means, and collecting means for removing the lint and other large solids from said edge.
 9. In the system of claim 7 wherein said screen means comprises a stationary flat perforated member having a planar surface facing said discharge means, and said screen cleaning means comprises scraping means movable across said planar surface to at least periodically remove accumulated lint and other large solids from said surface.
 10. In the system of claim 7 wherein said screen means is circular and said screen cleaning means rotates relative to said circular screen means.
 11. In the system of claim 1 wherein said receiving means comprises sump means, conduit means for removing solvent from said sump means and returning said solvent to said receptacle at a predetermined maximum flow rate, and wherein said control means controls the discharge rate of said solvent from said receptacle such that said discharge rate is greater than said predetermined maximum flow rate when said solvent is being discharged to said screen means, but to maintain the solvent level in said sump means out of contact with said screen means.
 12. In the system of claim 11 including filter means in said conduit means between said sump means and said receptacle.
 13. In the system of claim 11 wherein said control means initiates discharge of said solvent from said receptacle when the level of the solvent in said sump is at a predetermined minimum level and stops said discharge when the level of the solvent in said sump is at a predetermined maximum level at which maximum level the solvent is out of contact with said screen means.
 14. A method of removing lint and other large solids from the cleaning solvent of an article cleaning system, comprising the steps of: discharging at least a portion of the cleaning solvent from the cleaning receptacle upon screen means and at a location spaced from said screen means, flowing the discharged solvent through said screen means while retaining the lint and other large solids on said screen means, removing the cleaning solvent which flows through said screen means from said screen means, and controlling the rate at which the cleaning solvent is discharged upon the screen means from the receptacle in response to the level and flow rate of the solvent which has flowed through said screen means to continuously maintain the cleaning solvent which is removed from said screen means out of contact with said screen means.
 15. The method of claim 14 including at least periodically removing the lint and other large solids from said screen means by moving said lint and other large solids across said screen means, and collecting the removed lint and other large solids at a location spaced from the portion of said screen means upon which said cleaning solvent is discharged from said receptacle.
 16. The method of claim 14 wherein the solvent which is removed from said screen means is collected in a sump, and the rate at which the cleaning solvent is discharged from said receptacle is controlled in response to the level of solvent collected in said sump.
 17. The method of claim 14 including returning at least a portion of the cleaning solvent which passes through said screen means to said receptacle, and wherein the rate at which the cleaning solvent is discharged from said receptacle when it is being discharged is greater than the maximum rate at which said solvent is returned to said receptacle, whereby the amount of solvent in the recePtacle varies.
 18. The method of claim 17 wherein the solvent which is removed from said screen means is collected in a sump, and wherein said cleaning solvent is discharged from said receptacle in response to the level of solvent in said sump, and said solvent in said sump is returned to said receptacle.
 19. The method of claim 17 wherein said cleaning solvent is periodically discharged from said receptacle to said screen means and a portion of the solvent is continuously returned from said sump to said receptacle.
 20. The method of claim 14 including forming a ring of lint and other large solids on the screen means about the location that the cleaning solvent is discharged upon said screen means.
 21. In a cleaning system, an article cleaning receptacle adapted to clean articles with a cleaning solvent contained therein, screen means for removing lint and other large solids from the cleaning solvent, discharge means on said receptacle for discharging said cleaning solvent from said receptacle onto said screen means, receiving means including an outlet for receiving cleaning solvent from which said lint and other large solids have been removed from said screen means, and control means controlling the flow of said cleaning solvent through said discharge means in response to the flow rate from said receiving means of the solvent from which said lint has been removed to continuously maintain the solvent from which said lint and other large solids have been removed out of contact with said screen means.
 22. In the system of claim 21, wherein said cleaning solvent is discharged from said discharge means onto said screen means at a location spaced above said screen means.
 23. In the system of claim 21, wherein said receiving means for removing cleaning solvent comprises sump means, said control means maintaining the level in said sump means out of contact with said screen means.
 24. In the system of claim 21, including sump means and second discharge means communicating said sump means with said receptacle for returning cleaning solvent to said receptacle, and means to control the rate that said cleaning solvent is discharged to said screen means such that it is greater than the rate that said cleaning solvent is returned to said receptacle.
 25. In the system of claim 24 wherein said control means includes means capable of stopping the flow through the discharge means.
 26. In the system of claim 21, including screen cleaning means for removing lint and other large solids which have accumulated on said screen means.
 27. In the system of claim 26 wherein said screen cleaning means comprises means which moves the accumulated lint and other large solids to an edge of said screen means, and collecting means for removing the lint and other large solids from said edge.
 28. In the system of claim 26 wherein said screen means comprises a stationary flat perforated member having a planar surface facing said discharge means, and said screen cleaning means comprises scraping means movable across said planar surface to at least periodically remove accumulated lint and other large solids from said surface.
 29. In the system of claim 26 wherein said screen means is circular and said screen cleaning means rotates relative to said circular screen means.
 30. In the system of claim 21 wherein said receiving means comprises sump means, conduit means for removing solvent from said sump means and returning said solvent to said receptacle at a predetermined maximum flow rate, and wherein said control means controls the discharge rate of said solvent from said receptacle such that said discharge rate is greater than said predetermined maximum flow rate when said solvent is being discharged to said screen means, but to maintain the solvent level in said sump means out of contact with said screen means.
 31. In the system of claim 30 including filter means in said conduit means between said sump means and said receptacle.
 32. A method of removing lint and other large solids from the cleaning solvent of an article cleaning system, comprising the steps of: discharging at least a portion of the cleaning solvent from the cleaning receptacle upon screen means and at a location spaced from said screen means, flowing the discharged solvent through said screen means while retaining the lint and other large solids on said screen means, removing the cleaning solvent which flows through said screen means from said screen means, and controlling the rate at which the cleaning solvent is discharged upon the screen means from the receptacle in response to the flow rate of the solvent which has flowed through said screen means to continuously maintain the cleaning solvent which is removed from said screen means out of contact with said screen means.
 33. The method of claim 32 including at least periodically removing the lint and other large solids from said screen means by moving said lint and other large solids across said screen means, and collecting the removed lint and other large solids at a location spaced from the portion of said screen means upon which said cleaning solvent is discharged from said receptacle.
 34. The method of claim 32 including returning at least a portion of the cleaning solvent which passes through said screen means to said receptacle, and wherein the rate at which the cleaning solvent is discharged from said receptacle when it is being discharged is greater than the maximum rate at which said solvent is returned to said receptacle, whereby the amount of solvent in the receptacle varies.
 35. The method of claim 34 wherein said cleaning solvent is periodically discharged from said receptacle to said screen means and a portion of the solvent is continuously returned from said sump to said receptacle.
 36. The method of claim 32 including forming a ring of lint and other large solids on the screen means about the location that the cleaning solvent is discharged upon said screen means. 